Implant system

Abstract

A self-expansible structure for implantation in a body cavity is provided. The structure has a generally tubular outline, a nominal length, a nominal diameter, and a unique behavior under constraint. The unique behavior is expressed by a transition diameter, at which a constrained behavior of the structure changes so that, at a constraining diameter smaller than the transition diameter, the structure conforms to the constraint by decreasing the structure's diameter, to below the nominal diameter, and elongating beyond the nominal length, while at a constraining diameter larger than the transition diameter but smaller than the nominal diameter, the structure conforms to the constraint by decreasing the structure's diameter below the nominal diameter, while substantially maintaining the nominal length. Thus, the structure is operable for insertion into a body cavity, via a catheter, having a catheter inner diameter smaller than the transition diameter, by decreasing the structure's diameter, and elongating, and the structure is operable for implantation in the body cavity, having a cavity inner diameter greater than the transition diameter but smaller than the nominal diameter, by decreasing the structure's nominal diameter, while substantially maintaining the nominal length. The value of the transition diameter may be varied and controlled by the manner of constraining in the catheter, during insertion. In the preferred embodiment, the structure is formed of two closed wire constructions, shaped as symmetric wings, and has no exposed tips. The structure may be a stent. Alternatively, the structure may be an anchor, for mounting an incorporeal device thereon.

What is claimed is:  
     
         1 . A self-expansible structure, for implantation in a body cavity, said structure comprising: 
 a generally tubular outline;    a nominal length;    a nominal diameter; and    a transition diameter, at which a constrained behavior of said structure changes so that: 
 at a constraining diameter smaller than said transition diameter, said structure conforms to the constraint by decreasing the structure's diameter, to below the nominal diameter, and elongating beyond the nominal length, and  
 at a constraining diameter larger than said transition diameter but smaller than the nominal diameter, said structure conforms to the constraint by decreasing the structure's diameter below the nominal diameter, while substantially maintaining the nominal length,  
   wherein: 
 said structure is operable for insertion into a body cavity, via a catheter, having a catheter inner diameter smaller than said transition diameter, by decreasing the structure's diameter, while elongating, and  
 said structure is operable for implantation in the body cavity, having a cavity inner diameter greater than said transition diameter but smaller than the nominal diameter, by decreasing the structure's nominal diameter, while substantially maintaining the nominal length.  
   
     
     
         2 . The self-expansible structure of  claim 1 , wherein said structure is a stent, designed to provide structural support to a blood vessel.  
     
     
         3 . The self-expansible structure of  claim 1 , wherein said structure is an anchor, designed to support an intracorporeal device thereon.  
     
     
         4 . The self-expansible structure of  claim 3 , wherein said anchor further includes an intracorporeal device, mounted thereon, adapted for performing a physiologically related task at the body cavity.  
     
     
         5 . The self-expansible structure of  claim 4 , wherein said intracorporeal device is selected from the group consisting of a pressure sensor, a flow rate sensor, a temperature sensor, an oxygen concentration sensor, an ion concentration sensor, an impedance sensor, a sensor adapted for cardiac output assessment, a blood filter, a septal occluder, a coil, a detachable coil for aneurysm treatment, a graft, and a deflector.  
     
     
         6 . The self-expansible structure of  claim 3 , wherein said anchor further includes a carrier for mounting an intracorporeal device thereon.  
     
     
         7 . The self-expansible structure of  claim 1 , wherein the nominal length is at least 25% greater than the nominal diameter.  
     
     
         8 . The self-expansible structure of  claim 1 , wherein the nominal diagonal is at least 25% greater than the nominal diameter.  
     
     
         9 . The self-expansible structure of  claim 1 , wherein said structure is formed of at least one closed wire construction, thus having no exposed tips.  
     
     
         10 . The self-expansible structure of  claim 1 , wherein said structure is formed of at least two closed wire constructions, thus having no exposed tips.  
     
     
         11 . The self-expansible structure of  claim 1 , wherein said structure defines a length axis, parallel to its length, and a point of midlength, on said length axis, and wherein said structure is symmetric with respect to a plane, orthogonal to said length axis, and crossing said length axis at said point of midlength.  
     
     
         12 . The self-expansible structure of  claim 1 , wherein: 
 said structure is formed of at least one closed wire construction, thus having no exposed tips, and    said structure defines a length axis, parallel to its length, and a point of midlength, on said length axis, and wherein said structure is symmetric with respect to a plane, orthogonal to said length axis, and crossing said length axis at said point of midlength.    
     
     
         13 . The self-expansible structure of  claim 1 , wherein said structure is formed of a shape memory alloy, having a martensite phase at temperatures below body temperature and an austenite phase at temperatures at and above body temperature, and wherein said structure is at the martensite phase, at the martensite temperatures, when constrained in said catheter, for insertion into the body.  
     
     
         14 . The self-expansible structure of  claim 13 , wherein said structure is at the austenitic phase, at the austenitic temperatures, when implanted in the body cavity.  
     
     
         15 . The self-expansible structure of  claim 13 , wherein said structure is at a stress-induced martensite phase, at the austenitic temperatures, when implanted in the body cavity.  
     
     
         16 . The self-expansible structure of  claim 1 , wherein said structure is formed of a shape memory alloy, having an austenite phase and a stress induced martensite phase at and above room temperature, and wherein said structure is at the stress-induced martensite phase, both when constrained in said catheter, for insertion into the body, and when implanted in the body cavity.  
     
     
         17 . The self-expansible structure of  claim 1 , wherein in the deployed state, a perimeter of said structure forms an arc that is at least as great as half the cavity perimeter.  
     
     
         18 . The self-expansible structure of  claim 1 , wherein in the deployed state, a perimeter of said structure forms an arc that is at least as great as two thirds the cavity perimeter.  
     
     
         19 . The self-expansible structure of  claim 1 , wherein said structure is formed of a wire of a diameter of between 0.03 and 1.0 mm.  
     
     
         20 . The self-expansible structure of  claim 1 , wherein said structure is formed of a wire of a diameter of between 0.2 and 0.3 mm.  
     
     
         21 . The self-expansible structure of  claim 1 , wherein the value of said transition diameter may be varied and controlled by the manner of constraining in said catheter, during insertion.  
     
     
         22 . The self-expansible structure of  claim 1 , wherein said structure further includes at least one inner component for engaging with a retrieval instrument.  
     
     
         23 . An implant system, comprising: 
 a self-expansible structure, for implantation in a body cavity, said structure comprising: 
 a generally tubular outline;  
 a nominal length;  
 a nominal diameter; and  
 a transition diameter, at which a constrained behavior of said structure changes so that: 
 at a constraining diameter smaller than said transition diameter, said structure conforms to the constraint by decreasing the structure's diameter below the nominal diameter and elongating beyond the nominal length, and  
 at a constraining diameter larger than said transition diameter but smaller than the nominal diameter, said structure conforms to the constraint by decreasing the structure's diameter below the nominal diameter, while substantially maintaining the nominal length,  
 
 wherein: 
 said structure is operable for insertion into a body cavity, via a catheter, having a catheter inner diameter smaller than said transition diameter, by decreasing the structure's diameter, while elongating, and  
 said structure is operable for implantation in the body cavity, having a cavity inner diameter greater than said transition diameter but smaller than the nominal diameter, by decreasing the structure's nominal diameter, while substantially maintaining the nominal length; and  
 
   an intracorporeal device, mounted on said self-expansible structure and adapted for performing a physiologically related task at the body cavity.    
     
     
         24 . The implant system of  claim 23 , wherein said intracorporeal device is selected from the group consisting of a pressure sensor, a flow rate sensor, a temperature sensor, an oxygen concentration sensor, an ion concentration sensor, an impedance sensor, a sensor adapted for cardiac output assessment, a blood filter, a septal occluder, a coil, a detachable coil for aneurysm treatment, a graft, and a deflector.  
     
     
         25 . The implant system of  claim 23 , wherein said intracorporeal device comprises at least two intracorporeal devices.  
     
     
         26 . The implant system of  claim 23 , wherein said intracorporeal device comprises a power source.  
     
     
         27 . The implant system of  claim 23 , wherein said intracorporeal device comprises an extracorporeally energizeable power source.  
     
     
         28 . The implant system of  claim 23 , wherein said intracorporeal device is capable of telemetric communication with an extracorporeal device.  
     
     
         29 . The implant system of  claim 23 , wherein the nominal length is at least 25% greater than the nominal diameter.  
     
     
         30 . The self-expansible structure of  claim 23 , wherein the nominal diagonal is at least 25% greater than the nominal diameter.  
     
     
         31 . The implant system of  claim 23 , formed of at least one closed wire construction, thus having no exposed tips.  
     
     
         32 . The implant system of  claim 23 , formed of at least two closed wire constructions, thus having no exposed tips.  
     
     
         33 . The implant system of  claim 23 , wherein said structure defines a length axis, parallel to its length, and a point of midlength, on said length axis, and wherein said structure is symmetric with respect to a plane, orthogonal to said length axis, and crossing said length axis at said point of midlength.  
     
     
         34 . The implant system of  claim 23 , wherein: 
 said structure is formed of at least one closed wire construction, thus having no exposed tips, and    said structure defines a length axis, parallel to its length, and a point of midlength, on said length axis, and wherein said structure is symmetric with respect to a plane, orthogonal to said length axis, and crossing said length axis at said point of midlength.    
     
     
         35 . The implant system of  claim 23 , wherein said structure is formed of a shape memory alloy, having a martensite phase at temperatures below body temperature and an austenite phase at temperatures at and above body temperature, and wherein said structure is at the martensite phase, at the martensite temperatures, when constrained in said catheter, for insertion into the body.  
     
     
         36 . The implant system of  claim 35 , wherein said structure is at the austenitic phase, at the austenitic temperatures, when implanted in the body cavity.  
     
     
         37 . The implant system of  claim 35 , wherein said structure is at a stress-induced martensite phase, at the austenitic temperatures, when implanted in the body cavity.  
     
     
         38 . The implant system of  claim 23 , wherein said structure is formed of a shape memory alloy, having an austenite phase and a stress induced martensite phase at and above room temperature, and wherein said structure is at the stress-induced martensite phase, both when constrained in said catheter, for insertion into the body, and when implanted in the body cavity.  
     
     
         39 . The implant system of  claim 23 , wherein in the deployed state, a perimeter of said structure forms an arc that is at least as great as half the cavity perimeter.  
     
     
         40 . The implant system of  claim 23 , wherein in the deployed state, a perimeter of said structure forms an arc that is at least as great as two thirds the cavity perimeter.  
     
     
         41 . The implant system of  claim 23 , wherein said structure is formed of a wire of a diameter of between 0.03 and 1.0 mm.  
     
     
         42 . The implant system of  claim 23 , wherein said structure is formed of a wire of a diameter of between 0.2 and 0.3 mm.  
     
     
         43 . The implant system of  claim 23 , wherein the value of said transition diameter may be varied and controlled by the manner of constraining in said catheter, during insertion.  
     
     
         44 . The implant system of  claim 23 , wherein said structure further includes at least one inner component for engaging with a retrieval instrument.  
     
     
         45 . A retrieval system, comprising: 
 a self-expansible structure, for implantation in a body cavity, said structure comprising: 
 a generally tubular outline;  
 a nominal length;  
 a nominal diameter; and  
 a transition diameter, at which a constrained behavior of said structure changes so that: 
 at a constraining diameter smaller than said transition diameter, said structure conforms to the constraint by decreasing the structure's diameter below the nominal diameter and elongating beyond the nominal length, and  
 at a constraining diameter larger than said transition diameter but smaller than the nominal diameter, said structure conforms to the constraint by decreasing the structure's diameter below the nominal diameter, while substantially maintaining the nominal length,  
 
 wherein: 
 said structure is operable for insertion into a body cavity, via a catheter, having a catheter inner diameter smaller than said transition diameter, by decreasing the structure's diameter, while elongating, and  
 said structure is operable for implantation in the body cavity, having a cavity inner diameter greater than said transition diameter but smaller than the nominal diameter, by decreasing the structure's nominal diameter, while substantially maintaining the nominal length,  
 
   wherein: 
 said structure includes at least one inner component for engaging with a retrieval instrument, and  
 said retrieval system includes a retrieval instrument, mounted on a retrieval catheter, adapted for percutaneous insertion into the body cavity, for engaging with said inner component and for retrieving said structure.  
   
     
     
         46 . The retrieval system of  claim 45 , wherein said structure further includes an intracorporeal device, mounted thereon, adapted for performing a physiologically related task at the body cavity.  
     
     
         47 . A method of implanting a self-expansible structure, comprising: 
 providing a self-expansible structure, for implantation in a body cavity, said structure comprising: 
 a generally tubular outline;  
 a nominal length;  
 a nominal diameter; and  
 a transition diameter, at which a constrained behavior of said structure changes so that: 
 at a constraining diameter smaller than said transition diameter, said structure conforms to the constraint by decreasing the structure's diameter below the nominal diameter and elongating beyond the nominal length, and  
 at a constraining diameter larger than said transition diameter but smaller than the nominal diameter, said structure conforms to the constraint by decreasing the structure's diameter below the nominal diameter, while substantially maintaining the nominal length;  
 
   constraining said structure within a catheter, having a catheter diameter smaller than said transition diameter, wherein said structure conforms to said catheter by decreasing the structure's diameter and elongating;    inserting said catheter and structure to a body cavity, having a cavity diameter larger than said transition diameter but smaller than the nominal diameter; and    deploying said structure in the body cavity, wherein said structure conforms to the cavity by decreasing the structure's diameter, while substantially maintaining the nominal length.    
     
     
         48 . The method of  claim 47 , wherein said structure is a stent, designed to provide structural support to a blood vessel.  
     
     
         49 . The method of  claim 47 , wherein said structure is an anchor, designed to support an intracorporeal device thereon.  
     
     
         50 . The method of  claim 49 , wherein said anchor further includes an intracorporeal device, mounted thereon, adapted for performing a physiologically related task at the body cavity.  
     
     
         51 . The method of  claim 50 , wherein said intracorporeal device is selected from the group consisting of a pressure sensor, a flow rate sensor, a temperature sensor, an oxygen concentration sensor, an ion concentration sensor, an impedance sensor, a sensor adapted for cardiac output assessment, a blood filter, a septal occluder, a coil, a detachable coil for aneurysm treatment, a graft, and a deflector.  
     
     
         52 . The method of  claim 49 , wherein said anchor further includes a carrier for mounting an intracorporeal device thereon.  
     
     
         53 . The method of  claim 47 , wherein the nominal length is at least 25% greater than the nominal diameter.  
     
     
         54 . The method of  claim 47 , wherein the nominal diagonal is at least 25% greater than the nominal diameter.  
     
     
         55 . The method of  claim 47 , wherein said structure is formed of at least one closed wire construction, thus having no exposed tips.  
     
     
         56 . The method of  claim 47 , wherein said structure is formed of at least two closed wire constructions, thus having no exposed tips.  
     
     
         57 . The method of  claim 47 , wherein said structure defines a length axis, parallel to its length, and a point of midlength, on said length axis, and wherein said structure is symmetric with respect to a plane, orthogonal to said length axis, and crossing said length axis at said point of midlength.  
     
     
         58 . The method of  claim 47 , wherein: 
 said structure is formed of at least one closed wire construction, thus having no exposed tips, and    said structure defines a length axis, parallel to its length, and a point of midlength, on said length axis, and wherein said structure is symmetric with respect to a plane, orthogonal to said length axis, and crossing said length axis at said point of midlength.    
     
     
         59 . The method of  claim 47 , wherein said structure is formed of a shape memory alloy, having a martensite phase at temperatures below body temperature and an austenite phase at temperatures at and above body temperature, and wherein said structure is at the martensite phase, at the martensite temperatures, when constrained in said catheter, for insertion into the body.  
     
     
         60 . The method of  claim 59 , wherein said structure is at the austenitic phase, at the austenitic temperatures, when implanted in the body cavity.  
     
     
         61 . The method of  claim 59 , wherein said structure is at a stress-induced martensite phase, at the austenitic temperatures, when implanted in the body cavity.  
     
     
         62 . The method of  claim 47 , wherein said structure is formed of a shape memory alloy, having an austenite phase and a stress induced martensite phase at and above room temperature, and wherein said structure is at the stress-induced martensite phase, both when constrained in said catheter, for insertion into the body, and when implanted in the body cavity.  
     
     
         63 . The method of  claim 47 , wherein in the deployed state, a perimeter of said structure forms an arc that is at least as great as half the cavity perimeter.  
     
     
         64 . The method of  claim 47 , wherein in the deployed state, a perimeter of said structure forms an arc that is at least as great as two thirds the cavity perimeter.  
     
     
         65 . The method of  claim 47 , wherein said structure is formed of a wire of a diameter of between 0.03 and 1.0 mm.  
     
     
         66 . The method of  claim 47 , wherein said structure is formed of a wire of a diameter of between 0.2 and 0.3 mm.  
     
     
         67 . The method of  claim 47 , wherein the value of said transition diameter may be varied and controlled by the manner of constraining in said catheter, during insertion.  
     
     
         68 . The method of  claim 47 , wherein said method further includes retrieving said structure.  
     
     
         69 . A self-expansible structure, for implantation in a body cavity, wherein said self-expansible structure is formed of at least one closed wire construction, thus having no exposed tips.  
     
     
         70 . A self-expansible structure, for implantation in a body cavity, wherein said self-expansible structure is symmetric with respect to a plane, orthogonal to a length axis of said structure and crossing said length axis at a point of midlength of said structure.  
     
     
         71 . A self-expansible structure, for implantation in a body cavity, wherein; 
 said self-expansible structure is formed of at least one closed wire construction, thus having no exposed tips; and    said self-expansible structure is symmetric with respect to a plane, orthogonal to a length axis of said structure and crossing said length axis at a point of midlength of said structure.    
     
     
         72 . An implant system comprising: 
 a self-expansible structure, for implantation in a body cavity, wherein said self-expansible structure is formed of at least one closed wire construction, thus having no exposed tips; and    an intracorporeal device, mounted on said self-expansible structure and adapted for performing a physiologically related task at the body cavity.    
     
     
         73 . An implant system comprising: 
 a self-expansible structure, for implantation in a body cavity, wherein said self-expansible structure is symmetric with respect to a plane, orthogonal to a length axis of said structure and crossing said length axis at a point of midlength of said structure; and    an intracorporeal device, mounted on said self-expansible structure and adapted for performing a physiologically related task at the body cavity.    
     
     
         74 . An implant system comprising: 
 a self-expansible structure, for implantation in a body cavity, wherein; 
 said self-expansible structure is formed of at least one closed wire construction, thus having no exposed tips; and  
 said self-expansible structure is symmetric with respect to a plane, orthogonal to a length axis of said structure and crossing said length axis at a point of midlength of said structure; and  
   an intracorporeal device, mounted on said self-expansible structure and adapted for performing a physiologically related task at the body cavity.